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प्रश्न
Find the odd one out and give its explanation.
विकल्प
Tinning
Alloying
Anodization
Froth floatation
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उत्तर
Froth floatation
Explanation-
Froth floatation is a method used for the concentration of ores while others are methods used for the prevention of corrosion.
APPEARS IN
संबंधित प्रश्न
Which metals do not corrode easily?
Explain why rusting of iron objects is faster in coastal areas than in deserts.
What special name is given to the corrosion of iron?
The chemical reaction involved in the corrosion of iron metal is that of ______.
Name the metal which is used for galvanising iron.
State two conditions for the rusting of iron.
Tiffin boxes are electroplated with ______ but car bumpers are electroplated with ______ to protect them from rusting.
Explain why, though aluminium is more reactive than iron, yet there is less corrosion of aluminium when both are exposed to air.
What is corrosion?
Name any two metals which do not corrode easily.
Name two metals which resist corrosion due to the formation of a thin, hard and impervious layer of oxide on their surface.
What are the special properties of stainless steel?
A common metal which is highly resistant to corrosion is ______.
Bronze is an alloy of ______.
What is corrosion? What are necessary conditions for corrosion?
Compare roasting and calcination.
Explain with reason:
Roasting is carried out on sulphide ores and not on carbonate ores.
No chemical reaction takes place when granules of a solid, A, are mixed with the powder of another solid, B. However when the mixture is heated, a reaction takes place between its components. One of the products, C, is a metal and settles down in the molten state while the other product, D, floats over it. It was observed that the reaction is highly exothermic.
(i) Based on the given information make an assumption about A and B and write a chemical equation for the chemical reaction indicating the conditions of reaction, physical state of reactants and products and thermal status of reaction.
(ii) Mention any two types of reactions under which above chemical reaction can be classified.
Answer the following question:
What is corrosion? Do gold ornaments corrode? Justify.
Write three methods of preventing rusting of iron.
What is ‘rusting’?
Explain the term – rusting and give a word equation for the formation of rust. If polished iron nails are kept in three separate test tubes, state the contents in each test tube required, to prove the conditions for rusting.
_______ is an alloy made from iron, carbon and chromium.
Corrosion of silver causes a black layer of _______.
Stainless steel is an alloy of _______.
Find the odd one out and give its explanation.
Write the name.
An alloy of copper and tin-
State two conditions necessary for rusting of iron.
Amalgam is an alloy of ____________.
The diagram shows the reaction between metal and dil. acid.
What is the reason for different behaviour of Mg in test tube B?
Marble’s popularity began in ancient Rome and Greece, where white and off-white marble were used to construct a variety of structures, from hand-held sculptures to massive pillars and buildings.
The substance not likely to contain CaCO3 is:
A man painted his main gate made up of iron, to
- prevent it from rusting.
- protect it from sun.
- make it look beautiful.
- make it dust free.
Which of the above statement(s) is/are correct?
Iron pillar near the Qutub Minar in Delhi is famous for the following facts. Which of these facts is responsible for its long stability?
Explain the following:
Lime water turns milky on passing carbon dioxide gas into it.
Give an example of a chemical reaction for the following situation:
Sound is produced
Give scientific reasons.
Silver amalgam is used for filling dental cavities.
